Rear Shifting Problems

[Ajax Bay]

Can you post a photo of the jockey wheels taken side-on? It sounds as if they may be worn.

I don't think the symptoms described can be related to worn jockey wheels (but is there a thread hijacking here?)
For info, my ninjas needed replacing (see image; includes relatively new one for comparison). I suspect that they were the originals (ie with the 105 RD) so had about 20,000km on them.

 

[nmfeb70]

Ok, so I've included pics of the rear mech from all angles and as you can see, the jockey wheels are directly below the smallest cog when the chain is on the middle front ring. I've included a video which demonstrates my problem of the chain not dropping onto the smallest cog when on the largest front chainring. Can anyone spot something wrong which I've missed?

 

[nmfeb70]

I'll try again!

 

[Ajax Bay]

Good images but not from the angle needed. From the rear please, chain on the large chainring, cable unclamped, chain on smallest sprocket
PS Pulley wheels are fine (of course).

 

[nmfeb70]

And again!

 

[nmfeb70]

Again!

 

[Ajax Bay]

Rear Mech alignment looks OK (@screenman ?)
If the RD cage, with cable unclamped, will not push across (by hand) to line up with the smallest sprocket (and therefore initiate the shift to that sprocket), then unscrew the H limit screw edit: (as @Globalti said yesterday at 1733) till it does (but no further). Clamp the cable. Index as per video @Cycleops is always ready to share.

 

[nmfeb70]

Again..cannot post vid.

 

[nmfeb70]

Rear Mech alignment looks OK (@screenman ?)
If the RD cage, with cable unclamped, will not push across (by hand) to line up with the smallest sprocket (and therefore initiate the shift to that sprocket), then unscrew the H limit screw till it does (but no further). Clamp the cable. Index as per video @Cycleops is always ready to share.

Derailleur cage works ok when moved by hand but refuses to drop onto smallest cog. Will try the H limit screw.

 

[nmfeb70]

I can't believe a half turn of the H screw was all it needed. Of course that seemed to obvious to me, who tends to overcomplicate matters! Cheers everyone!

 

[C R]

I can't believe a half turn of the H screw was all it needed. Of course that seemed to obvious to me, who tends to overcomplicate matters! Cheers everyone!

Glad you sorted it, simple problems with simple solutions are the most common.

 

[Gunk]

It could be the cable in your shifter is not correctly set up, pull on the cable hard and shift as you are changing down to the smallest cog.

Release the cable from the mech, make sure the derailleur moves freely by hand from small to the largest cog and make sure all the barrel adjusters are screwed in, with the chain on the smallest cog tighten the cable in the rear mech, you should be able to make final adjustments using the barrel adjusters

 

[Illaveago]

It seems strange that it was just the limit screw preventing it from selecting top gear when it would in the lower range chainring ? Possibly a slight change in angle ?

 

[nmfeb70]

It seems strange that it was just the limit screw preventing it from selecting top gear when it would in the lower range chainring ? Possibly a slight change in angle ?

Yes I found it odd. Hence the reason why I never thought of adjusting the limit screws. Works perfectly now on both chainrings.

 

[MrGrumpy]

Unless it's so worn as to be sloppy a derailleur will go on working for years.

New derailleur arrived yesterday , fitted setup , seems to have fixed my issues. Lower jockey wheel had collapsed. Suspect it worked fine with a worn stretched chain but with a new chain , no chance !